Our findings did not support an association between miR-100 rs1834306, miR-124-1 rs531564, miR-605 rs2043556 and miR-4293 rs12220909 polymorphism and the risk of BC.
The pre-miR-605 rs2043556-C allele was associated with a decreased risk of BC, both in patients with a strong family history of BC and in early-onset non-familial BC (Odds ratio (OR) = 0.5 [95% confidence interval (CI) 0.4⁻0.9] <i>p</i> = 0.006 and OR = 0.6 [95% CI 0.5⁻0.9] <i>p</i> = 0.02, respectively).
To explore the relevance of miRNA polymorphisms and female physiological characteristics to breast cancer risk, SNPs located within hsa-miR-605 (rs2043556), hsa-miR-149 (rs2292832), hsa-miR-27a (rs895819), hsa-miR-196a-2 (rs11614913) and hsa-miR-618 (rs2682818) were selected, and their associations with breast cancer risk were analysed.